1. Field of the Invention
The present invention relates to a rope termination and to a method of terminating a rope for lifting or hoisting applications. In particular, the present invention is directed to a rope termination device for lifting or hoisting applications wherein a rope may be secured to a termination device in the field without tools or fasteners and wherein the rope is self-tightening to the termination device.
2. Description of the Related Art
Rope termination devices or elements utilized for lifting or hoisting of loads are used in a wide variety of applications.
Wire rope termination fittings come in a variety of configurations including those shown in Applicant's prior U.S. Pat. No. 6,170,145 entitled Method Of Securing A Termination Element To An End Portion Of A Wire Rope.
In addition, some types of terminations require clamps, clips or other elements secured at or near the end of the rope.
More recently, various types of synthetic rope have been employed for lifting or hoisting of loads.
Synthetic ropes or cables may be woven or braided of individual strands or otherwise constructed of polymer material, such as nylon, polyester or other materials. Synthetic ropes are known to have excellent load limits while being relatively lightweight and durable.
Synthetic rope or cable is negatively impacted by cuts, cracks or breaks, excessive wear, nicks, gouges or damage from heat or sunlight. Synthetic rope should be protected from being cut or abraded by sharp corners, sharp edges or sharp bends. Synthetic ropes which suffer cuts, nicks or gouges are to be taken out of service.
Synthetic rope or cable is negatively impacted by cracks or breaks, excessive wear, nicks, gouges or damage from heat or sunlight. When a rope or cable is bent, the working load limit of the rope is reduced by a bending factor. The bending factor (EB) can be calculated according to the formula:
      E    B    =      1    -          0.5                        D          /          d                    
The diameter D represents the diameter of the element around which the rope or cable is bent. The diameter d represents the diameter of the entire rope or cable. The D/d ratio is the ratio of the diameter around which the rope is bent divided by the diameter of the rope or cable.
It will thus be appreciated that the rope or cable has an efficiency related to the various D/d ratios.
Various types of termination devices have been suggested in the past for ropes or cables. For example, procedures for termination of synthetic rope include hand splicing, mechanical splicing, and/or fusing of the synthetic rope.
Smith et al. (U.S. Pat. No. 8,096,024) discloses a rope termination device for an aramid-based rope having a socket 90 with a tapered passageway to accept a conical wedge 100.
Dupont (U.S. Pat. No. 7,228,599) discloses a cord clasp 10 for a cord including a synthetic cord, terminating for transmitting a tensile load such as a bicycle braking actuator.
Shaw (U.S. Pat. No. 5,136,755) discloses an end clamp having a pair of tapered elements for a composite rope.
Morris et al. (U.S. Pat. No. 2,595,806) discloses a rope fitting including a body member 2 having an axial bore 4 therethrough. The rope passes through the bore 4 and then around peripheral groove 11. The end 15 of the rope is retained under a loop portion of the rope.
Notwithstanding the foregoing, it is desirable to provide a synthetic rope termination for lifting or hoisting applications.
It would further be desirable to provide a synthetic rope termination which can be installed or rigged in the field without any tools or fasteners.
It would further be desirable to provide a synthetic rope termination wherein the rope is self-tightening to the termination device.
It would further be desirable to provide a synthetic rope termination that minimizes bends in the rope in order to maximize the efficiency of the device or fitting.